1. Field of the Invention
The present invention relates to gyrosensors used in automobile navigation systems or used for performing position-controlling or correcting hand-shaking occurring in image pick-up apparatuses.
2. Related Background Art
Gyrosensors are finding widespread use in automobile navigation systems or shake isolating devices used in image pick-up apparatuses. Among such gyrosensors, vibrating gyrosensors, which are inexpensive and yet obtain high-precision angular velocities, are well known.
More specifically, the following gyrosensors disclosed in Japanese Patent Laid-Open Nos. 3-54414, 3-172713, and 7-092175 have been proposed. In such gyrosensors, if a vibrator is activated and an angular velocity is applied to the vibrator, a Coriolis force is generated. Due to this Coriolis force, the vibrator changes its state of vibration, and such changes are detected, thereby determining the amount and the direction of the angular velocity.
In the above gyrosensors, in order to improve the detecting performance, however, it is required that the amplitude and the frequency of vibrations be increased and the mass of the vibrator be also raised. Further, precise machining may be required for obtaining a correct difference between the two outputs from the gyrosensor, or subtle-adjustments may be needed after assembly.
Because of the above drawbacks, the miniaturization of the gyrosensors is restricted, and a reduction in the cost of the gyrosensors is also limited.